Northside Health Library

Rectal culture

Definition

Rectal culture is a laboratory test to identify bacteria and other germs in the rectum that can cause gastrointestinal symptoms and disease.

Alternative Names

Culture - rectal

How the Test is Performed

A cotton swab is inserted into the rectum, rotated gently, and removed. A smear of the swab is placed in culture media to encourage the growth of bacteria and other organisms. The laboratory technician watches the culture for growth.

When growth is observed, the organisms can be identified. Further tests to determine the best treatment may also be done.

How to Prepare for the Test

The health care provider does the rectal examination and collects the specimen.

How the Test Will Feel

There may be pressure as the swab is inserted into the rectum, but the test is usually not painful.

Why the Test is Performed

The test is performed if your health care provider suspects that you have an infection of the rectum. It may be done when gonorrhea is suspected. It may also be done as an alternative to a fecal culture if it is not possible to get a specimen of feces.

The rectal culture may also be performed in a hospital or nursing home setting to see if someone carries vancomycin-resistant enterococcus (VRE) in their intestine, which can be spread to other patients.

Normal Results

Finding bacteria and other germs that are usually found in the body is normal.

Normal value ranges may vary slightly among different laboratories. Talk to your health care provider about the meaning of your specific test results.

What Abnormal Results Mean

Abnormal results may mean you have an infection, such as bacterial or parasitic enterocolitis or gonorrhea. Sometimes a culture shows that you are a carrier, but you may not have an infection.